多校冲刺 noip 11.07
作者：互联网
多校冲刺 noip 11.07
今天挂了\(160pts\)，本来\(AK\)了
这两天题真水，水展了。
T1 石子合并
考场上好久才想到只有一个减号的构造方法，最后因为没有判\(n==1\)挂成\(60pts\)
AC_code
#include<bits/stdc++.h>
using namespace std;
#define fo(i,x,y) for(int i=(x);i<=(y);i++)
#define fu(i,x,y) for(int i=(x);i>=(y);i--)
const int N=2e6+5;
const int inf=2e9+1;
int T,n,a[N];
int ans,mn,fl_del,fl_add,fl_nan;
signed main(){
freopen("stone.in","r",stdin);
freopen("stone.out","w",stdout);
scanf("%d",&T);
while(T--){
scanf("%d",&n);
fo(i,1,n)scanf("%d",&a[i]);
ans=0;mn=inf;
fl_add=fl_del=fl_nan=0;
fo(i,1,n){
if(a[i]>0)fl_add++;
else if(a[i]<0)fl_del++;
else fl_nan++;
ans=max(ans+a[i],ans-a[i]);
mn=min(mn,abs(a[i]));
}
if(fl_nan)ans=ans;
else if(!fl_del)ans-=2*mn;
else if(!fl_add)ans-=2*mn;
if(n==1)ans=a[1];
printf("%d\n",ans);
}
return 0;
}
T2 翻转游戏
一看这就是扫描线大板子！！于是有了下面这一百行
扫描线
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fo(i,x,y) for(int i=(x);i<=(y);i++)
#define fu(i,x,y) for(int i=(x);i>=(y);i--)
const int N=3e5+5;
int T,p,q,n,ans;
int xa[N],xb[N],ya[N],yb[N];
struct scan{
int x,yl,yr,tp;
scan(){}
scan(int a,int b,int c,int d){x=a;yl=b;yr=c;tp=d;}
bool operator < (scan a)const{
return x<a.x;
}
}sca[N];
int lsh[N*2],lh;
struct XDS{
#define ls x<<1
#define rs x<<1|1
int s1[N*8],t1[N*8],s2[N*8],t2[N*8],tg[N*8];
void pushup(int x){
if(t1[ls]==t1[rs]){
t1[x]=t1[ls],s1[x]=s1[ls]+s1[rs];
t2[x]=max(t2[ls],t2[rs]);s2[x]=0;
if(t2[ls]==t2[x])s2[x]+=s2[ls];
if(t2[rs]==t2[x])s2[x]+=s2[rs];
}
else if(t1[ls]>t1[rs]){
t1[x]=t1[ls],s1[x]=s1[ls];
t2[x]=max(t2[ls],t1[rs]);s2[x]=0;
if(t2[ls]==t2[x])s2[x]+=s2[ls];
if(t1[rs]==t2[x])s2[x]+=s1[rs];
}
else {
t1[x]=t1[rs],s1[x]=s1[rs];
t2[x]=max(t2[rs],t1[ls]);s2[x]=0;
if(t2[rs]==t2[x])s2[x]+=s2[rs];
if(t1[ls]==t2[x])s2[x]+=s1[ls];
}
return ;
}
void pushdown(int x){
tg[ls]+=tg[x];tg[rs]+=tg[x];
t1[ls]+=tg[x];t2[ls]+=tg[x];
t1[rs]+=tg[x];t2[rs]+=tg[x];
tg[x]=0;return ;
}
void build(int x,int l,int r){
tg[x]=0;
if(l==r){
t1[x]=0;s1[x]=lsh[l+1]-lsh[l];
t2[x]=-1;s2[x]=0;
return ;
}
int mid=l+r>>1;
build(ls,l,mid);
build(rs,mid+1,r);
pushup(x);return ;
}
void ins(int x,int l,int r,int ql,int qr,int v){
if(ql>qr)return ;
if(ql<=l&&r<=qr){
tg[x]+=v;t1[x]+=v;t2[x]+=v;
return ;
}
if(tg[x])pushdown(x);
int mid=l+r>>1;
if(ql<=mid)ins(ls,l,mid,ql,qr,v);
if(qr>mid)ins(rs,mid+1,r,ql,qr,v);
pushup(x);return ;
}
#undef ls
#undef rs
}xds;
signed main(){
freopen("carpet.in","r",stdin);
freopen("carpet.out","w",stdout);
scanf("%lld",&T);
while(T--){
scanf("%lld%lld%lld",&p,&q,&n);ans=0;
fo(i,1,n){
scanf("%lld%lld%lld%lld",&xa[i],&ya[i],&xb[i],&yb[i]);
lsh[i*2-1]=ya[i];lsh[i*2]=yb[i];
sca[i*2-1]=scan(xa[i],ya[i],yb[i],1);
sca[i*2]=scan(xb[i],ya[i],yb[i],-1);
}lh=n*2;
sort(lsh+1,lsh+lh+1);
lh=unique(lsh+1,lsh+lh+1)-lsh-1;
xds.build(1,1,lh);int sum;
sort(sca+1,sca+2*n+1);
fo(i,1,n*2){
sca[i].yl=lower_bound(lsh+1,lsh+lh+1,sca[i].yl)-lsh;
sca[i].yr=lower_bound(lsh+1,lsh+lh+1,sca[i].yr)-lsh-1;
//cout<<sca[i].yl<<" "<<sca[i].yr<<endl;
xds.ins(1,1,lh,sca[i].yl,sca[i].yr,sca[i].tp);
if(i!=n*2){
sum=(xds.t1[1]>=n-1?xds.s1[1]:0)+(xds.t2[1]>=n-1?xds.s2[1]:0);
ans+=(sca[i+1].x-sca[i].x)*sum;
}
}
printf("%lld\n",ans);
}
return 0;
}
于是只有\(50pts\)
于是发现只有\(n+1\)种情况，于是切掉了
AC_code
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fo(i,x,y) for(int i=(x);i<=(y);i++)
#define fu(i,x,y) for(int i=(x);i>=(y);i--)
const int N=3e5+5;
int T,p,q,n,ans;
int xa[N],xb[N],ya[N],yb[N];
int pxa[N],pxb[N],pya[N],pyb[N];
void maxx(int x,int y,int z){
pxa[z]=max(pxa[x],xa[y]);
pxb[z]=min(pxb[x],xb[y]);
pya[z]=max(pya[x],ya[y]);
pyb[z]=min(pyb[x],yb[y]);
}
signed main(){
freopen("carpet.in","r",stdin);
freopen("carpet.out","w",stdout);
scanf("%lld",&T);
while(T--){
scanf("%lld%lld%lld",&p,&q,&n);ans=0;
fo(i,1,n){
scanf("%lld%lld%lld%lld",&xa[i],&ya[i],&xb[i],&yb[i]);
}
memset(pxa,0,sizeof(pxa));
memset(pxb,0x3f,sizeof(pxb));
memset(pya,0,sizeof(pya));
memset(pyb,0x3f,sizeof(pyb));
fo(i,1,n)maxx(i-1,i,i);
fu(i,n,1){
pxa[n+1]=max(pxa[i-1],pxa[n+2]);
pxb[n+1]=min(pxb[i-1],pxb[n+2]);
pya[n+1]=max(pya[i-1],pya[n+2]);
pyb[n+1]=min(pyb[i-1],pyb[n+2]);
int x=pxb[n+1]-pxa[n+1];if(x<0)x=0;
int y=pyb[n+1]-pya[n+1];if(y<0)y=0;
ans+=x*y;
maxx(n+1,i,n+1);
x=pxb[n+1]-pxa[n+1];if(x<0)x=0;
y=pyb[n+1]-pya[n+1];if(y<0)y=0;
if(i!=1)ans-=x*y;
maxx(n+2,i,n+2);
}
printf("%lld\n",ans);
}
return 0;
}
T3 优美的旋律
因为一个字写错了，挂掉\(60pts\)
咋做都行， 直接枚举
AC_code
#include<bits/stdc++.h>
using namespace std;
#define ull unsigned long long
#define fo(i,x,y) for(int i=(x);i<=(y);i++)
#define fu(i,x,y) for(int i=(x);i>=(y);i--)
const int N=3005;
const int bas=131;
int a,b,n,ans;
char s[N];
ull hs[N],ba[N],cf[N][N];
int ys[N][N],pd[N][N];
ull get(int l,int r){return hs[r]-hs[l-1]*ba[r-l+1];}
signed main(){
freopen("melody.in","r",stdin);
freopen("melody.out","w",stdout);
// cout<<(sizeof(cf)*3>>20)<<endl;
scanf("%d%d",&a,&b);
scanf("%s",s+1);n=strlen(s+1);
ba[0]=1;fo(i,1,n){
ba[i]=ba[i-1]*bas;
hs[i]=hs[i-1]*bas+s[i]-'a';
}
fo(i,1,n){
cf[i][1]=1;
fo(j,2,n/i)cf[i][j]=cf[i][j-1]*ba[i]+1;
}
fo(i,1,n){
int now=i;
fo(j,2,sqrt(now))
if(now%j==0){
ys[i][++ys[i][0]]=j;
while(now%j==0)now/=j;
}
if(now!=1)ys[i][++ys[i][0]]=now;
}
fo(i,1,n){
fo(j,1,i){
ull ha=get(j,i);
int len=i-j+1;
if(!ys[len][0]){pd[j][i]=1;continue;}
pd[j][i]=1;
fo(k,1,ys[len][0]){
if(get(j,len/ys[len][k]+j-1)*cf[len/ys[len][k]][ys[len][k]]==ha){
ans=max(ans,max(len/ys[len][k]*a+ys[len][k]*b,len/ys[len][k]/pd[j][len/ys[len][k]+j-1]*a+ys[len][k]*pd[j][len/ys[len][k]+j-1]*b));
pd[j][i]=ys[len][k]*pd[j][len/ys[len][k]+j-1];break;
}
}
}
}
printf("%d",ans);
return 0;
}
T4 基站建设
咋做都行，\(\mathcal{O(能过)}\)
AC_code
#include<bits/stdc++.h>
using namespace std;
#define fo(i,x,y) for(int i=(x);i<=(y);i++)
#define fu(i,x,y) for(int i=(x);i>=(y);i--)
const int N=50005;
const int M=2e5+5;
int n,m,ans;
int r[N];
int to[M*2],nxt[M*2],head[N],rp;
int du[N];
void add_edg(int x,int y){
to[++rp]=y;
nxt[rp]=head[x];
head[x]=rp;
}
int fa[N],siz[N];
int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
vector<int> vec[N];
bool com(int x,int y){return x>y;}
void spj(){
fo(i,1,n)vec[find(i)].push_back(r[i]);
fo(i,1,n)if(find(i)==i){
if(vec[i].size()<4)continue;
sort(vec[i].begin(),vec[i].end(),com);
ans=max(ans,(vec[i][0]+1)*(vec[i][1]+1)+vec[i][2]*vec[i][3]);
}
printf("%d",ans);
}
queue<int> q;
bool vis[N];
signed main(){
freopen("station.in","r",stdin);
freopen("station.out","w",stdout);
scanf("%d%d",&n,&m);
fo(i,1,n)scanf("%d",&r[i]);
fo(i,1,n)fa[i]=i,siz[i]=1;
fo(i,1,m){
int x,y;scanf("%d%d",&x,&y);
add_edg(x,y);add_edg(y,x);
du[x]++;du[y]++;
int fx=find(x),fy=find(y);
if(fx==fy)continue;
if(x<y)siz[fx]+=siz[fy],fa[fy]=fx;
else siz[fy]+=siz[fx],fa[fx]=fy;
}
bool fl=true;
fo(i,1,n)if(du[i]!=siz[find(i)]-1)fl=false;
if(fl){spj();return 0;}
int sb=clock();
fo(i,1,n){
for(int j=head[i];j;j=nxt[j])q.push(to[j]),vis[to[j]]=true;
while(!q.empty()){
int x=q.front(),mx=0,mi=0;q.pop();
for(int j=head[x];j;j=nxt[j]){
if(!vis[to[j]])continue;
if(r[to[j]]>mx)mi=mx,mx=r[to[j]];
else if(r[to[j]]>mi)mi=r[to[j]];
}
if(mx&&mi)ans=max(ans,(r[i]+1)*(r[x]+1)+mx*mi);
if(clock()-sb>=5600000){printf("%d",ans);return 0;}
}
for(int j=head[i];j;j=nxt[j])vis[to[j]]=false;
}
printf("%d",ans);
return 0;
}
标签：noip,rs,int,11.07,t2,多校,lsh,ans,fo 来源： https://www.cnblogs.com/hzoi-fengwu/p/15520024.html